Report: We control many breast cancer risk factors

Report: We control many breast cancer risk factors

SAN ANTONIO (AP) ---- Women concerned about breast cancer should
worry less about cellphones and hair dyes and worry more about
weighing or drinking too much, exercising too little, using
menopause hormones and getting too much radiation from medical
tests. So says a recent report on environmental risks by a
respected panel of science advisers.

By environment they mean everything not governed by genes ----
what's in the air and water but also diets, vitamin use and even
things like working night shifts.

And while they lament that most chemicals in consumer goods get
little safety testing, they find too few studies in people to say
whether there is a breast cancer risk from certain pesticides,
cosmetics or bisphenol A, known as BPA and used in many plastics
and canned food liners, although it has been eliminated from baby
bottles and many reusable beverage containers in recent years.

"We don't have enough data to say 'toss your water bottles,'"
said Irva Hertz-Picciotto, chief of environmental and occupational
health at UC Davis.

She headed the Institute of Medicine panel ---- independent
experts under the National Academy of Sciences who advise the
government and others.
This
report
was paid for by Susan G. Komen for the Cure, a breast
cancer foundation. It was presented in December at a
cancer conference
in Texas.

We've done a better job of treating breast cancer than
preventing it, said Dr. Michael Thun, senior epidemiologist for the
American Cancer Society, who helped review the report. Breast
cancer death rates in the U.S. fell 31 percent from 1990 to 2007,
but incidence rates declined only about 5 percent.

Weight and obesity matter because fat cells make estrogen, and
that hormone fuels the growth of most breast cancers, he said.

Other factors are more complex. Moderate alcohol consumption may
lower the risk of heart disease, but seems to raise the risk of
breast cancer a little.

The report sorts the evidence for higher breast cancer risk
factors like this:

Yes:
Hormone therapy combining estrogen and
progestin, excess weight after menopause, alcohol consumption and
radiation from too many medical tests, especially during childhood.
The panel doesn't say how much radiation is too much, but says two
or three abdominal CT scans give as much as atomic bomb survivors
received. Mammograms use minuscule amounts and should not be
avoided. Oral contraceptives slightly raise breast cancer risk
while taken, although cancer rates are very low in the age groups
that use them.

No:
Hair dyes and the kind of radiation from
cellphones, microwaves and electronic gadgets.

Probable:
Smoking.

Possible:
Secondhand smoke, nighttime shift
work and exposure to benzene and a couple of other chemicals
through jobs or from breathing car fumes or pumping gas. It is
"biologically plausible" that BPA and certain other plastics
ingredients might affect estrogen, which fuels most breast cancers,
but evidence is mostly in animals and lab tests ---- not enough to
judge whether they harm people, the panel concluded.

"There's a tremendous desire to blame someone or something" for
breast cancer, said Dr. Eric Winer, a cancer specialist at
Dana-Farber Cancer Institute in Boston and chief scientific adviser
to the Komen Foundation.